In The Secret Doctrine? (October 1888) by Helene P. Blavatsky Vol. 1 page 554 till 566 is explained that inventor Keely| already demonstrate his Compound Disintegrator (Picture 1,2,3,4,5,6,7) with the sentence "Had Keely been permitted to succeed, he might have reduced a whole army to atoms in the space of a few seconds as easily as he reduced a dead ox to the same condition". Also inventor Nikola Tesla invented a Death Ray machine, see also an article about him in the New York Times (September 11, 1940).